Page 279 - Practical Ship Design

Design of Lines 237

Fig. 8.3. Tunnel form to permit use of a larger propeller.

Great Laker Ocean-going ship
"Canadian Enterprise" "Canadian Pioneer"

Fig. 8.4. Two Port Weller bulk carriers with semi-tunnel single-screw forms to permit use of a
larger propeller.

A glance at the designs shown in the 1990 and 1991 numbers of Significant
Ships shows that the "Mariner" or clear water type of stern mentioned in (iii) above
and shown in Fig. 8.5 is now almost universally adopted.

8.2.7 Stern lines above the propeller

It is very desirable from a resistance point of view that the stem lines above the
propeller should be continued to form a cruiser stem which is immersed at the
operating drafts. As Fig. 8.5 shows, a cruiser stem should extend aft sufficiently to
cover the rudder but there is no need for there to be any significant immersion at the
end of the waterline; indeed, significant immersion at this point is likely to cause
eddies particularly if the cruiser stem is terminated by a flat transom as has become